MRCU Resumes Night Flights

The Mosquito Research and Control Unit (MRCU) recently resumed night aerial spraying operations, albeit with a degree of caution.

Since Hurricane Ivan, MRCU had suspended night flights because of the number of unlit and damaged communication towers, cranes, and antennae, as well as the lack of street lights that made flying at night hazardous.

They did, however, undertake nighttime fogging from trucks, and so far that initiative, combined with daytime aerial efforts, has paid off. Much of the success is due to intensified larviciding operations, using the equivalent of a year’s supply of larvicide. “We saved the island from a massive mosquito problem,” says MRCU Chief Dr. Bill Petrie. “In our view, daylight aerial operations dispersing larvicide pellets over problem areas, and night-time fogging from trucks have controlled mosquitoes effectively.”

And now the resumption of nighttime flying (itself a significant part of the recovery process for MRCU) is contributing to a greater level of comfort in the department – and for the population as well.

Among the data department chiefs considered in their decision to resume night flights were maps using GPS technology. Created by Assistant Director of Research and Development Dr Alan Wheeler, the maps detail the location of all tall towers and antennae across Grand Cayman. The investigation revealed that nearly all towers are now lit, and, along with improved street lighting, this has added up to an overall positive environment for night flying.

The group, which included Chief Pilot Richard Clough, opted for a cautious approach. Once data gathered from mosquito traps indicated a problem, the pilot would conduct two daytime safety flights. The first reconnaissance flight would check for new obstacles in the area to be sprayed and the second flight, just prior to sunset, would cover the same area, checking that obstacles such as cranes and towers were lit for the evening.

Mosquitoes are most active from dusk to one hour after sunset, making this the optimal time for low-altitude flights, since the larvicide sprayed from the plane hits the mosquitoes when they are flying.

During November, MRCU conducted two trial aerial spraying flights at sunset to test the effectiveness of spraying from higher altitudes.